Arc-lamp.



G. M- LITTLE.

ARG LAMP. APPLICATION FILED MAY'IO, 190s.

Patented Sept, 14, 1909.

Big 7.

WITNESSES ATTORNEY.

UNITED ST ATEs PifENT OFFICE. I

GEORGE- M. LITTLE, OF rrrzrsnunermmsrnvanm, ASSIGNOR '10 wnstrmenousn E ECTRIC & MANUFAC'I 1'0 all whom it may concern: w

f Be it known that I, GEOR M. Lrrrnn, a

cltizen of the United States and a resident t 3 of Pittsburg, in the county of Aollegheny and g 5 State of Pennsylvania, have invented a new and useful Improvement in TArc-Larnps, of

which the following is a specification. I

My invention relates to a amps and it has for its object to provide means for automatically preventing the fo i 'nation of deposits upon the globes whicliusurround the arcs and for causing the electrodes to be. evenly and squarely consumed.v

Arc lamps have heretofor been provided --with composition electrodes of such character that the arcs produced ire more luminous than those produced iloetween plain carbon electrodes, and also such that they are less rapidl consumed. A composition which has been ound suitable comrises magnetic ,oxid of iron, which is usual the predominant constituent and whiclnlflg ives conduc-,

tivity to the, electrode both when hot and when cold, chromium oxid, hich by reason l t of its very high fusing pointlassists in preventing rapid consumptionof the electrode it and flickering of the-arc, and titannun oxid which imparts color and brilliancy to the arc the life of the and also assists in extendin I electrode; Such an' electrode s usually employed as the cathode in combination with a copper or other suitable metallic anode, the

latter being but very slowly consumed by the are. Fumes are ordinarily-given off at the arcs between such'eloctrodes and are condensed and deposited upon the metallic electrode and the globe within which'the electrodes are usually inclosetlj. The cathode is often consumed unevenlylfand its end be- 0 comes beveled and, in order lc ause the composition electrode to be consumed evenly and squarely and also to preventfithe fumes glven,

off by the are from depositing upon the 1nclosing globe, I propose to direct a draft of .45 clean air upon the inner surface of the globe in such a manner as to ca a rotation of {the atmosphere snrrounding the electrodes, therebycausing the arc to I tlitealso.

Figure" 1 of the accomp lying drawings he casing of an arc lamp that is construct l in accordance withmy invention, Fig. 2 i a sectional view on the line IL-II of Fig Fig. 3 is, a

plan view of a IIlQdlfiCtltQll of the part is a view in section' througl ARC-LAMP.

Spebifidaltion of Letters Patent. Application filed May 10, 1806. Serial No. 316,135.

ING COMPANY, A CORPORATION PENNSYLVANIA.

Patented sepam, 1909.

shown in Fig, 2, and Fig.,4= is a sectional view on the line.IV-IV of Fig. 3.

An electrode 1 that may be com' osed, as before described, of magnetic oxi of iron and oxids of titanium and chromium or of other substances in various and suitable proportions, is adaptedvto be adjusted in posi tion with reference to' anotherelectrode 2 1 by anysuitable means (not shown) such as isconnnonly employed for "the purpose. In the present instance, electrode 1 is surrounded 1 by a tube 3 which protrudes through the lower offset end of another tube or chimneys, currents of air being directed downwardly around the electrode by the tube 23 and immediately reversed and directed upwardly by the draft in the chimney 4, such structure forming the subject-matter of an- -other ap 'ilicatlon, Serial No. 316,132 filed by" me of even date herewith i The electrode 2 and the lower end ofthe electrode 1 are inclosed by a transparent globe 5 that is provided with a cap or closure dhaving apertures in its circumference in relation to which vanes 8 and 9 are so disposed upon the outer surfaces that drafts of clean air are directed upon the inner surface of the globe in a direction substantially tangential to its circumference. A rotating layer oft-lean air is thus formed 'ad acent to the inner surface of the globe so that the 8 fumes glven oil by the are do not come 111' contact therewith and consequently the formation of depositsthereon is sul'istantially prevented. Rotation of the atmosphere within the globe is also caused which in turn-.90 causes rotation of the arc. Rotation of thr arc prevents uneven consumption and hoveling. of the upper electrode which 'might otherwise occur. I in Fig. 25 Iv have shown a modification of the cap or closure of Figs L andv 2, the pas sages, through the cap beingat'ltl in its end surface rather than, in its circumferential, surface and the vanes 11 ii; so shaped and disposed as to direct; the drafts of air upon 0 the inner surface of the globe and cause rocomposed of glass or other transparent inatcrial so as not to obscure the light and cast shadows. 4 y Y The device here shown and described for directing the air upon the surface of the globe and causing rotation of the atmosphere within is only. illustrative of any broadly to cover every'such means.

1'. In an arc-lamp, the combination with rotation of the atmosphere within the casing suitable means fore-fleeting this result and I desire thatmy. invention be construed "I claim as my invention:

electrodes and an vinclosing' casing therefor, of means-for directing 'a draft upon the inner surfaceof the casing and for causing and approximately horizontally upon the inner surface of the casing.

3. In an arc lamp, the combination with electrodes and an inclosing casing therefor, of meansfor causing the drafts that enter the casing to revolve about an approximately vertical axis adjacent to the inner surface of the casing. i

In 'testimony whereof, I have hereunto subscribed my name this 1st day of May, 1906. GEORGE M. LITTLE.

Witnesses:

OTTO S. SGHAIRER, BIBNEY HINES. a 1 

